Microsatellite sequences are repetitive DNA sequences usually several base pairs in length. Microsatellite sequences are composed of non-coding DNA and are not parts of genes. They are used as genetic markers to follow the inheritance of genes in families.
A microsatellite. These are little bits of DNA in our genome that are very simple in the sense that they're only made up of two or three combinations of letters, like CACACA or GATGATGAT. And it turns out that these little repetitive sequences within our genome vary very quickly between different people. And so it's very easy [for] these microsatellite repetitive sequences to try and so-call fingerprint DNA with a particular human being.Elliott Margulies, Ph.D.